The FranX bot has a limited question databae. It is working fine. You can modify its database. Also FranX bot is a open source project. The code is really original. You can download it in the author site: http://www.viewpoint.cl
There are some bot in another language, but it is the only one in Actionscript 3. Also ALL the files are downloable (fla, swf, XML and a cool skin).